“Great care must be taken that the child be not frightened, and it must never be left alone, lest it be injured, by venemous Creatures, or some other external injuries, which they cannot resist, for it is known that Scorpions, Serpents, and such like Creatures have crept into Childrens mouths, or other wise injured them, or Cats by lying upon them have suffocated them.”
John Pechey, A General Treatise of the Diseases of Infants and Children
Hello, new parent! The seventeenth century would like to remind you that a whole army of scorpions, snakes, and maniacal housecats is just waiting for a chance to jump into that crib. Good luck sleeping now!
How to Raise Your Child, twelfth century, here.